A brand’s standing in one AI search engine predicts remarkably little about its standing in the next.

That’s the key finding in Semrush’s expanded 2026 AI Visibility Index, which analyzed 126 million U.S. AI search prompts collected between January and April 2026. The study tracked how ChatGPT, Google Gemini, Google AI Mode and Google AI Overviews describe and cite more than 1,200 brands across 22 industry verticals.¹

The headline number is a small one. Of those 1,200-plus brands, only 36 appeared in the top 100 most-mentioned list on every platform, in every month of the study window. All of them were household names like Google, Amazon, Facebook, Apple, Walmart, Disney, and Nintendo.

Everyone else had a gap somewhere.

Why this matters for brands

For most of the past two years, AI visibility has been discussed as a single score — either an AI system knows your brand or it doesn't. The Index points to something more uneven. A brand can be well represented in ChatGPT and effectively absent from Google's AI Mode, or strong in AI Overviews and missing from Gemini, because each platform assembles its answers from a different mix of sources.

The gap has a mechanical cause. Semrush found ChatGPT cites an average of 15 sources per response while Gemini cites three.¹ A brand that comfortably makes ChatGPT’s list can fall outside Gemini's much narrower one on the same question.

That has a practical consequence for planning. As teams build Q4 and 2027 budgets, an AI-visibility audit run on a single platform will systematically overstate how findable a brand actually is. Consistency comes from breadth: the brands that hold position everywhere are the ones whose names recur across the sources all four platforms draw on.

Where the platforms overlap

The sources these systems have in common lean heavily toward places where people are already discussing products, categories and tradeoffs in public: community and Q&A platforms, encyclopedic references, and long-running discussion threads. Those carry a structural advantage. They're continuously updated, they're written in the shape of questions people actually ask, and they contain the comparative language — "X vs. Y," "is X worth it" — that an AI answer needs in order to make a recommendation at all.

Quora sits in that overlap. It appears in over 7% of Google AI Mode responses and is the top-cited domain in Google AI Overviews.2 In Semrush's analysis of 278,000 prompts and 26,000 cited Quora URLs, the questions that earned citations averaged 37 replies and 15 upvotes² — which points to conversation depth as the thing these systems reward.

What consistency is worth

Cross-platform presence matters more than it sounds, because people arriving from AI search are further along. They've already had the category explained, the options compared and the tradeoffs summarized before they ever click. Semrush found that visitors arriving from AI search convert at 4.4 times the rate of visitors from traditional organic search.³

A brand missing from one platform goes absent at the exact moment a well-informed buyer is deciding which option to choose.

How to find your own gaps

Audit every surface separately. Run your twenty highest-intent category questions through ChatGPT, Gemini, AI Mode and AI Overviews individually, and record which brands and which sources appear in each. A single blended number hides the gap you're looking for.

Read the source list. The domains cited alongside your category are the map of where AI visibility gets built, and for most B2B categories that map includes community platforms no brand owns. Your own ranking is the smaller half of the story.

Participate where the answers come from. Presence on discussion platforms accrues from useful contribution over time: subject-matter experts answering real questions, consistently. A one-time content push leaves no trace in it.

Engage where decisions are being made

AI search now spans four surfaces, each of which needs checking on its own. The brands that show up consistently across them are the ones participating in the public conversations those systems read.

Increase your AI Search visibility on Quora with our 5-step action plan .

¹ Semrush, 2026 AI Visibility Index (June 2026)

² We Analyzed 26K Quora URLs Cited in Google AI Mode: Here’s What Works

³ We Studied the Impact of AI Search on SEO Traffic. Here’s What We Learned